China Eastern Airlines is to acquire 80 Boeing 737s, a mix of -800 and the re-engined Max variants.
The aircraft are due to be delivered in batches over 2016-20.
China Eastern says it has reached a purchase agreement with Boeing covering the acquisition. It says the value of the 80 aircraft, at list prices, is $7.387 billion.
While the airline has not broken down the deal by model, the overall value indicates that it comprises 60 737 Max jets and 20 737-800s.
All 737-800s are powered by CFM International CFM56s while the Max will have CFM Leap-1B engines.
As part of the agreement China Eastern will sell 15 737-300s as well as five 757s.
It says the 737s date from 1991-98, averaging 17.2 years, while the 757s are 2004-05 models averaging 9.6 years. The aircraft have a book value of 1.52 billion yuan ($245 million).
China Eastern recently opted to take 70 Airbus A320neo jets under a transaction which also included the sale of Airbus A300s.